Differentiation from embryonic stem cells to vascular wall cells under in vitro pulsatile flow loading.
Differentiation from embryonic stem cells to vascular wall cells under in vitro pulsatile flow loading.
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DOI：
10.1007/s10047-005-0291-2
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发表时间：
2005-01-01
期刊：
影响因子：
--
通讯作者：
Nemoto, Yasushi
中科院分区：
文献类型：
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作者：
Huang, Haiying;Nakayama, Yasuhide;Nemoto, Yasushi
本研究通过体外物理(机械)应力负荷实验，探讨了胚胎干细胞向血管壁细胞分化的可能性。将含有来自小鼠胚胎干细胞的Flk1阳性细胞(约30%)的细胞混合物加入到由分段聚氨酯制成的顺应性微孔管中。该管的顺应性与人体动脉接近[硬度参数(β)=57.2(n=5，SD<；5%)]。在血管内皮生长因子(VEGF)存在下预培养两天，管腔表面完全被细胞覆盖。在静态条件下，在没有血管内皮生长因子的情况下额外孵育2天后，生长的细胞分层，主要是平滑肌肌动蛋白(SMA)阳性的细胞，仅在管腔表面观察到。细胞呈扁平、多边形、随机取向。另一方面，在模拟人体静脉系统的弱脉动血流下孵育2天后[壁切应力(WSS)从-0.98到2.2dyn/cm(2)；周向应变(CS)4.6-9.6×10(4)dyn/cm(2)]，浅层细胞沿脉动血流方向规则定向。定向培养的细胞呈内皮样，提示为血小板内皮细胞黏附分子1(PECAM1)阳性。此外，生长在深层空隙中的细胞呈平滑肌样外观，表明它们为SMA阳性。WSS和CS的结合可能同时鼓励向两种不同的细胞类型分化和融合的ES细胞的分离。通过ES细胞的物理同步分化，有望构建由几种血管壁细胞类型组成的层次化结构的混合型血管假体。
This study evaluated the possibility of differentiation from embryonic stem (ES) cells to vascular wall cells by physical (mechanical) stress loading in vitro. A cell mixture containing Flk1-positive cells (ca. 30%) derived from murine ES cells was added to a compliant microporous tube made of segmented polyurethane. The compliance of the tube was close to that of the human artery [the stiffness parameter (beta) = 57.2 (n = 5, SD < 5%)]. The luminal surface of the tube was fully covered with the cells by preincubation for two days in the presence of vascular endothelial growth factor (VEGF). After 2 days of additional incubation without VEGF under static conditions, layering of the grown cells, mostly smooth muscle actin (SMA)-positive cells, was observed only on the luminal surface of the tube. The cells were flat, polygonal, and randomly oriented. On the other hand, after a 2-day incubation under a weak pulsatile flow simulating the human venous systems [wall shear stress (WSS) from -0.98 to 2.2 dyn/cm(2); circumferential strain (CS) 4.6-9.6 x 10(4) dyn/cm(2)] without VEGF, cells in the superficial layer were regularly oriented in the direction of the pulsatile flow. The oriented cells exhibited endothelial-like appearance, indicating that they were platelet endothelial cell adhesion molecule 1 (PECAM1)-positive. In addition, the cells growing into the interstices in the deeper layer showed smooth muscle-like appearance, indicating that they were SMA-positive. Differentiation to two different cell types and segregation of incorporated ES cells may be simultaneously encouraged by the combination of WSS and CS. It is expected that the monobloc building of hierarchically structured hybrid vascular prostheses composed of several vascular wall cell types is possible by physically synchronized differentiation of ES cells.